【摘要】 目的:研究噬菌体鸡尾酒混合制剂对牛奶中产志贺毒素大肠杆菌O157:H7的抑制作用研究。方法:采用双层平板法,以产志贺毒素大肠杆菌O157:H7 ATCC 43895为宿主菌,从污水中分离裂解性噬菌体。通过体外抑菌试验研究其在牛奶样品中的抑菌效果。结果:噬菌体C13.6、C13.9和C34.6的噬菌斑透亮清晰;能裂解宿主菌ATCC 43895及其他O157:H7大肠杆菌,为宽宿主谱;噬菌体鸡尾酒混合制剂对牛奶中O157:H7大肠杆菌的抑菌效果为:在25℃条件下,MOI=10,处理2 h及以上抑菌效果极其显著,在10 h时宿主菌数量下降4.30 (lg(CFU/mL))。结论:该噬菌体混合制剂对牛奶中O157:H7大肠杆菌有良好的抑制作用,具有作为食品防腐剂的潜能。更多还原

【Abstract】 Objective: To investigate the inhibitory effect of phage cocktail mixture on Shiga toxin producing E. coli O157:H7 in milk samples. Methods: The two-layer plate method was used to isolate the lytic phage from sewage with Shiga toxin producing Escherichia coli O157:H7 ATCC 43895 as the host bacteria. In addition, the antibacterial effect in milk samples was studied by antibacterial test in vitro. Results: The plaques of phages C13.6, C13.9 and C34.6 were clear. It can cleave the host bacteria ATCC 43895 and other O157:H7 Escherichia coli, which is a wide host spectrum; The bacteriostatic effect of phage cocktail mixture on E.coli O157:H7 in milk was as follows: at 25 ℃, MOI=10, the bacteriostatic effect was extremely significant after treatment for 2 h or more, and the number of host bacteria decreased by 4.30(lg(CFU/mL)) after treatment for 10 h. Conclusion: The phage cocktail had a good inhibitory effect on E. coli O157:H7 in milk, and had the potential as a food preservative.更多还原